The invention relates to a clothing ring for an opening roller of an open-end spinning device.
Clothing rings for the opening rollers of open-end spinning devices have been known for a long time in various embodiments and described in numerous patent documents. Opening rollers of this type are used, in particular, to open a fiber band (commonly referred to as a sliver) supplied in spinning cans to the workstations of an open-end spinning machine into individual fibers before being fed into a spinning means, revolving at a high rotational speed, of the open-end spinning device. Opening rollers of this type rotating at a high rotational speed, for this purpose, have on their periphery, a tearing structure which combs the fiber band supplied and in the process opens it into its individual fibers. The opening rollers differ inter alia with regard to their type of production and with regard to the configuration of their tearing tools.
Opening rollers are known, for example, which have a cylindrical ring being used as a needle carrier with numerous bores to receive needles. Clothing rings of this type equipped with individual needles, which are described, for example, in U.S. Pat. No. 4,798,046, have not proven successful, however. In other words, although the most varied forms of needles were tested, as described in U.S. Pat. No. 4,798,046, these needle roller rings did not succeed in practice.
On the other hand, wire clothing rings and so-called solid rings are widespread in practice.
Solid rings of this type are described in relative detail inter alia in German Patent Publication DE-OS 1 939 683 or in German Patent Publication DE 35 15 153 C2.
As shown in these patent documents, these solid rings have a clothing which in each case is manufactured in one piece from a solid hardened steel ring. In the case of clothing rings of this type, to form the tearing tool, at least one groove running helically in the peripheral direction and a plurality of indents extending substantially orthogonally thereto are cut into the lateral surface of the clothing ring. German Patent Publication DE 35 15 153 C2 shows and describes a solid ring, in this case, in which the separation spacing of the teeth predetermined by the groove running helically is about ⅓ smaller than the tooth height produced owing to the orthogonally extending indents. The solid rings according to German Patent Publication DE-OS 1 939 683 describe clothing rings which have relatively large axial separation spacings between the teeth and are equipped with teeth, the tooth height of which is relatively small, in other words, in these known clothing rings, the ratio of separation spacing/tooth height is about 4/1. Solid rings with a configuration as described in German Patent Publication DE-OS 1 939 683 were, however, not able to be successful on the market as the transporting behavior of these clothing rings proved to be inadequate, above all, because of the relatively small tooth height.
Even though solid rings in general are not only distinguished by a long service life, but also by good functionality, it is known that the combing out and transporting behavior of such clothing rings can be influenced by the shaping of the teeth, in particular by a special configuration of the tooth flanks of the teeth and/or the groove arranged between the teeth.
Clothing rings are described, for example, in German Patent Publication DE 100 54 448 A1, in which the groove arranged between the teeth is V-shaped to achieve particularly good drawing of the fibers during their transportation through the opening roller housing. In other words, the tooth flanks of the teeth, which are configured linearly and arranged at an inclination of <5° with respect to the tooth centre plane, pass into the side walls of the V-shaped groove with the formation of a bend edge. The side walls of the groove thus have an inclination of about 40° with respect to the tooth centre plane.
Clothing rings with teeth are also known from German Patent Publication DE 42 40 026 A1 and German Patent Publication DE 40 38 352 A1, in which, to achieve a combing out of the so-called fiber tuft of the fed fiber band, which is as good as possible and gentle, the tooth flanks are provided with a surface structure.
German Patent Publication DE 40 38 352 A1 in this case describes clothing rings, in which only the region of the tooth flanks has a surface structure of this type, while the surface in the region of the semi-circular groove arranged between the teeth is smooth.
In the clothing rings according to German Patent Publication DE 42 40 026 A1, not only the tooth flanks have a special profiling, but also the groove arranged between the teeth is provided with a corresponding profiling.
Finally, clothing rings are known from German Patent Publication DE 43 00 536 A1, which, between the teeth, have a helically running groove with a concavely curved groove base, adjoined by side walls of the groove arranged in an inclined manner.
The angle of inclination of the side walls of the groove, based on the centre plane of the teeth is about 15°. The tooth flanks of the teeth adjoin the side walls of the groove, in each case, similarly to the clothing rings according to German Patent Publication DE 100 54 448 A1, the angle of inclination of the tooth flanks being significantly smaller than the angle of inclination of the side walls of the groove. A configuration of this type leads to a bend edge also being produced here in each case between the side walls of the groove and the tooth flanks of the teeth. A bend edge of this type has a disadvantageous effect on the combing out behavior of the clothing ring. In other words, the fiber separation during the fiber band opening is to some extent inadequate, or inadequately uniform, in these known clothing rings.